Related papers: Virialization in Dark Energy Cosmology
Interacting dark energy and the holographic principle offer a possible way of addressing the cosmic coincidence problem as well as accounting for the size of the dark energy component. The equilibrium points of the Friedmann equations which…
We examine the evolution of a holographic cosmological model with future event horizon as the infrared cut-off and dark matter and dark energy do not evolve independently $-$ there is interaction between them. The basic evolution equations…
That decoherence can take place in the presence of energy conservation seems to be a poorly known fact. That lack of knowledge has for example bedevilled the discussion of the "black hole information" problem. I present a simple model which…
I examine differences in non-linear structure formation between cosmological models that share a $z=0$ linear power spectrum in both shape and amplitude, but that differ via their growth history. $N$-body simulations of these models display…
I briefly outline a new physical interpretation to the average cosmological parameters for an inhomogeneous universe with backreaction. The variance in local geometry and gravitational energy between ideal isotropic observers in bound…
One of the most important concepts in logic and the foundations of mathematics may be useful in providing an explanation for the cosmological constant problem. A connection between self-reference and consciousness has been previously…
We study a holographic model for the dark energy considered recently in the literature which postulates an energy density $\rho \sim R$, where $R$ is the Ricci scalar curvature. We obtain a cosmological scenario that comes from considering…
We study a holographic cosmological model in which the infrared cutoff is set by the Ricci's length and dark matter and dark energy do not evolve on their own but interact non-gravitationally with each other. This greatly alleviates the…
It has been persuasively argued that the number of the effective degrees of freedom of a macroscopic system is proportional to its area rather than to its volume. This entails interesting consequences for cosmology. Here we present a model…
We study the degeneracies between dark energy dynamics, dark matter and curvature using a non-parametric and non-perturbative approach. This allows us to examine the knock-on bias induced in the reconstructed dark energy equation of state,…
We investigate the holographic dark energy scenario with a varying gravitational constant, in flat and non-flat background geometry. We extract the exact differential equations determining the evolution of the dark energy density-parameter,…
We investigated evolution of metric and density perturbations for Tsallis model of holographic dark energy with energy density $\sim L^{2\gamma - 4}$, where $L$ is length of event horizon or inverse Hubble parameter and $\gamma$ is…
This work summarises some of the attempts to explain the phenomenon of dark energy as an effective description of complex gravitational physics and the proper interpretation of observations. Cosmological backreaction has been shown to be…
It has been proposed that the observed dark energy can be explained away by the effect of large-scale nonlinear inhomogeneities. In the present paper we discuss how observations constrain cosmological models featuring large voids. We start…
Cosmological models with different types of Dark Energy are becoming viable alternatives for standard models with the cosmological constant. Yet, such models are more difficult to analyze and to simulate. We present analytical…
Using the spherical collapse approach, we investigate the impact of two alternative dark matter models, each characterized by distinct non-zero equations of state, one constant and the other time dependent on the nonlinear regime.…
The present thesis is devoted to the reconstruction of the dark energy models using diverse observational data sets. The parametric approach has been adopted for the reconstruction of cosmological models. The reconstruction of kinematical…
The Starobinsky model of modified gravity suggested to explain dark energy may be also considered in the astrophysical context. Recently it has been pointed out that in contracting regions curvature oscillations around the GR value may lead…
Astrophysical observations are pointing out huge amounts of dark matter and dark energy needed to explain the observed large scale structures and cosmic accelerating expansion. Up to now, no experimental evidence has been found, at…
We consider holographic cosmological models of dark energy in which the infrared cutoff is set by the Hubble's radius. We show that any interacting dark energy model, regardless of its detailed form, can be recast as a non interacting model…